The present invention concerns a plug-in coupling for pressure application systems, consisting of two coupling components, namely a housing component and a connector component, whereby the connector component, is sealed insertable into a locating opening of the housing component, and is arrestable against loosening by a locking device, and whereby the locking device has an elastically deformable holding element, which is located on the side of one coupling component in such a way that, in the inserted state, it engages behind a resting step of the other coupling component, locking with positive fit, for arresting the connector component.
Such plug-in couplings have been known for a long time through numerous publications. Here, only GB-A-799 155 and EP-B-0 005 865 will be given as examples. In accordance with the former publication, a retaining ring is pre-assembled in a peripheral groove on the connector component. During insertion, the retaining ring becomes elastically, radially, inwardly deformed, i.e. contracted, over an inner cone surface in the mouth region of the housing component's locating opening. The latter publication describes examples in which a retaining ring or holding clip is inside an inner housing recess and, during the connector's insertion, becomes radially extended over an outer cone provided at its end, until it subsequently locks into an outer ring groove of the connector component.
The problem in known plug-in couplings like this, is that, in the design for high system pressures, the holding element has to be dimensioned sufficiently strong, with large cross section in particular, so that it can guarantee sufficiently high retention force to prevent loosening of the connector component. Because of the large radial forces required to deform the corresponding holding element, this leads to the disadvantage that very large mating forces are required for insertion. Currently, these even make plugging-in by hand impossible.
The objective of the present invention is to improve a plug-in coupling of the generic type such that relatively large retention forces are simultaneously guaranteed alongside relatively small mating forces, in such a way that manual plug-in is easily possible even in designs for high pressures.
This is attained, in accordance with the invention, in that the design of the holding element is ring-shaped and consists, in such a way, of several individual annular segments and one concentric spring lock washer component which presses the annular segments with radially operating spring resistance, that each annular segment can move radially against or through the spring resistance of the spring lock washer component during the plugging-in. Through this embodiment in accordance with the invention, the individual annular segments can themselves be designed relatively inelastic and dimensionally stable, and advantageously in fact with a basically rectangular annular cross section (as viewed in a radial section). An extraordinarily large retention force can be attained this way, while the mating force is advantageously small, because only the radial spring resistance of the spring lock washer component is operating during the radial movement of the individual annular segments (apart from friction). The mating force is thereby only determined by the spring lock washer component, which can be designed relatively soft to advantage, i.e. with small radial force. The mating force is thereby completely independent of the size of the holding element's circular cross section. An optimal locking action is moreover attained, in that each annular segment moves absolutely perfectly radially, without elastic deformation.
Additional advantageous characteristics of the invention are contained in the dependent claims and the following description.